Question

Bài 2 và bài 3 thôi ạ

 

Answer 1

Bài 3: 

Ta có: \(\sqrt{4x^2-12x+9}=4\)

\(\Leftrightarrow\left|2x-3\right|=4\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-3=4\\2x-3=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=7\\2x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)

Answer 2

Bài 2: 

a: Ta có: \(\sqrt{17-3\sqrt{32}}+\sqrt{17+3\sqrt{32}}\)

\(=\sqrt{17-12\sqrt{2}}+\sqrt{17+12\sqrt{2}}\)

\(=3-2\sqrt{2}+3+2\sqrt{2}\)

=6

b: Ta có: \(\sqrt{5+2\sqrt{6}}-\sqrt{5-2\sqrt{6}}\)

\(=\sqrt{3}+\sqrt{2}-\sqrt{3}+\sqrt{2}\)

\(=2\sqrt{2}\)